The present invention relates to an engine manufacturing and particularly to a connecting rod-piston assembly device.
In well-known construction of the connecting rod-piston assembly, the connection of the piston with the connecting rod is made by means of a piston pin in the form of a cylinder (xe2x80x9cAutomobile VAZxe2x80x9d, by Vershigora V. A.)
The disadvantage of such connection consists in that the axis of said piston pin is on the piston under a groove for the piston ring, which leads to the increasing of an overall engine dimension. In order to reduce such dimensions it is necessary to reduce the connecting rod length, but this action increases the mechanical loss. The present invention partially resolves this contradiction: such as, it provides the connecting rod-piston assembly, having small dimensions, but, at the same time, with greater theoretical length of the connecting rod.
The device, disclosed in Patent Application No97102529/06, filed on Feb. 18, 1997, ICL 6 F6J 1/22, named xe2x80x9cConnecting rod-piston unitxe2x80x9d, is taken as a prototype and has the similar technical essence.
The disadvantage of known device is an insufficient strength of an assembly on high revolutions of an engine. By increasing revolutions, the inertial loads increase sharply and, when the inertia forces of the piston are directed to the combustion chamber side and it is providing an assembly extension, a cross component force is appearing in said spherical connection of the connecting rod-piston, which deforms a skirt in this direction within the limits of the elastic deformation. As a result, the skirt diameter increases, the piston begins to stick within the cylinder and the mechanical loss increases.
Technical target of this invention is a simultaneous increasing piston strength and reducing cross component force, which leads to the skirt deformation.
Technical result is achieving by making an upper end of the connecting rod in said assembly in the form of a bowl-shaped element with straight truncated edges along the connecting rod width and with outer and inner spherical surfaces, the centres of which are located from a side of the engine combustion chamber. There is a partition in said piston with a cavity, made in the form of a slit, having big and small spherical surfaces with the side walls. At the ends of said cavity on one side of the partition there are side walls, which contact with one straight-line edge of said truncated bowl-shaped element of the connecting rod within the limits of a working swinging node of the connecting rod. There is also a channel, made in the partition to open a part of the cavity to pass a connecting rod blade there through. A bulkhead, being a part of a big sphere of the piston, is made on the piston partition, on the flank of said side walls from the big sphere of the piston to the piston skirt side. Said bulkhead connects said side walls and two opposite regions of the piston big sphere and partially shuts off the central channel of the piston parallel to the straight-line truncated edge of the connecting rod from the flank of the side walls and laps by its big sphere surface over the surface of the connecting rod outer sphere with the possibility of intercontacting on the width from the straight-line truncated edge of the bowl-shaped element to the connecting rod blade. The bulkhead and side walls, during a piston blank casting, are reinforced with strong material in the form of a thin plate, mounted along the piston partition and connecting side walls. On the piston partition end from the side of the piston skirt along its perimeter there is a groove, where there is positioned a ring of strong material, which embraces said piston partition together with the bulkhead and side walls. This groove is expanded after said unit assembling.
The bulkhead, made on the piston partition, increases the piston skirt strength in the lateral direction and simultaneously reduces side force, which deforms said piston skirt. The bulkhead, having big spherical surface, made on it, takes a part of the tensile forces of inertia, and while the angle of said forces application in the centre of the bulkhead is zero, a total cross component of these forces is reducing significantly. The bulkhead and piston side walls, reinforced by the plate, and the ring of strong material, embracing said partition, increase the strength of the piston skirt in the direction of cross forces of inertia. The whole unit in assembly is a balanced construction.
Suggested device allows not only the increasing of piston strength in the cross direction, but significantly reduces those forces, which act in this direction, that the lateral deformations of piston from the tensile forces of inertia reduce sharply for about the order and it is appearing a to utilize said spherical connection of the piston with the connecting rod in a high-speed engines. So, said device has an increased strength and improves the technical-and-economic index of an internal combustion engine.